Explicit elements of norm one for cyclic groups

Abstract

Let G be a cyclic p-group of order p^n acting by automorphisms on a (non-necessarily commutative) ring R. Suppose there is an element x in R such that (1 + t + ... + t^{p-1})(x) = 1, where t is an element of order p in G. We show how to construct an element y in R such that (1 + s + ... + s^{p^n-1})(y) = 1, where s is a generator of G.